This invention relates to safety shoes which employ rigid box toes, such as steel, to protect the wearer's foot in relatively hazardous environments such as factories, mines, athletic activities, etc. Safety shoes incorporating steel box toes have been in use for many years and can be considered as falling into a number of categories. For example, one such category includes shoes or boots molded from rubber or plastic which incorporate the steel toe but in which there are no lasting or pulling over procedures in the manufacture of the shoe or boot. Another type of steel box toe safety shoe includes a more conventional shoe construction in which an upper is pulled over about the last and is lasted to an insole held in place at the bottom of the last. The safety shoes of the type described may be further categorized and distinguished between those in which the steel box toe is located exteriorly of the upper and those in which the steel box toe is located interiorly of and is concealed by the upper. The present invention relates to improved techniques for manufacturing lasted safety shoes embodying steel box toes which are located beneath and are concealed by the shoe upper.
The manufacture of such shoes typically has presented a number of difficulties, one of which resides in the more complicated manufacturing technique as compared with the lasting of conventional shoes which do not include a steel safety box toe. For example, typical manufacturing procedures which have been employed to construct safety shoes having steel box toes generally require that the individual components of the shoe be built up, piece-by-piece on the last. This is a time consuming, expensive, and highly skilled procedure, all of which contributes to the higher cost of such shoes. Thus, with the typical prior art mode of manufacture, the insole first is temporarily secured to the last bottom. The upper assembly, which includes a lining over the inner surface of the upper, is placed over the last and must be located in proper position on the last. The lining then is pulled over and lasted to the insole in a first pulling over and lasting operation. At least the toe or vamp region of the upper itself necessarily remains unlasted so that it can be peeled back to enable the steel box toe to be inserted between the upper and its lining. After the lining has been securely lasted, the still unlasted upper is peeled back and the steel box toe is placed on the toe of the last over the lining. In addition, various strips of padding or other layers of cushioning material then may be built up on or about the steel box toe at this time. After the steel box toe and any other layers of material associated with it have been placed on the lasted lining, the upper itself then is pulled over and lasted. In some instances, the building up of the steel box toe and associated layers or strips of material also may require the application of an adhesive coating or activation of a previously formed adhesive layer.
From the foregoing, it will be appreciated that the manufacture of lasted steel box toe shoes requires numerous manipulative steps which necessarily increase the expense and skill required in the manufacture of such shoes. Nevertheless, the foregoing manufacturing techniques have been used for many years and still are in substantially widespread universal use.
It is among the primary objects of the invention to provide an improved technique for manufacturing lasted steel box toe safety shoes which avoids many of the foregoing difficulties and procedures.